File Handling In Pascal Binary Files Wiki Needs Work

[flywire]

I have been making the file handling examples in the tutorial executable but the Binary Files need a bit of work: http://wiki.freepascal.org/File_Handling_In_Pascal#Binary_files

The first one falls over at the seek and I don't understand the intended functionality.

[eny]

The code fragment is useless:
- the seek should not be there
- the buffer is written with random data (garbage)
So the title of this topic is well chosen

[Leledumbo]

The code fragment is useless:
- the seek should not be there
- the buffer is written with random data (garbage)
So the title of this topic is well chosen

Mind fixing it?

[eny]

Mind fixing it?

I assumed flywire was already on top of it 

[flywire]

Mind fixing it?

I have made extensive changes to this tutorial page but I can't understand this section so hopefully someone else can step it.

[Bart]

Made some changes.

Bart

[flywire]

These tutorials are a good resource but I would like to promote a bit of discussion on who the audience is for them? If it is newbies, and I can't see why it shouldn't be, then I think that the tutorials still assume too much. The Run-Time Library (RTL): Reference guide does a good job with plenty of executable examples.  For example, how does the user know which units have to be added to the uses clause? (I normally run them and do a search on the errors.) I would be useful to list them in the tutorial, and sysutils is not going to do it. Yes, I accept that changes are my responsibility too.

I tested the first two binary files examples and they work fine - good work fellas. The third one falls over at the end of 'FileStream := TFileStream.Create;'. Beats me - it works OK in the FileCopy example below. Thinking about it though, this not a very useful example and should probably be deleted and the FileCopy adjusted so that it works with large files.

[eny]

These tutorials are a good resource but I would like to promote a bit of discussion on who the audience is for them? If it is newbies, and I can't see why it shouldn't be, then I think that the tutorials still assume too much.

In this case the reviewed examples are clear enough.
It would be a waste of time to explain basic language elements on every page.
BTW (rhetorical question): what is the definition of newbies?

As for the units usage: I agree.
A code fragment that makes use of a specific class that requires a uses line, should make mention of that.

[marcov]

   For example, how does the user know which units have to be added to the uses clause? (I normally run them and do a search on the errors.)

Press "F1" on the symbol with help installed?

[eny]

Mind fixing it?

Done.

[flywire]

Done.

Just ran program ReadBinaryDataInMemoryForAppend because I need to.

Code: [Select]

    // Write some arbitrary data to the memory stream
    msApp.WriteByte(68);
    msApp.WriteAnsiString('Some extra text');
    msApp.WriteDWord(671202);
When I first looked at the result in Hex I thought it was screwed up but then I realised that this demo is really informative, especially in little endian. Well done.